org.apache.flink.runtime.blob

Class BlobCache

java.lang.Object

org.apache.flink.runtime.blob.BlobCache

All Implemented Interfaces:

BlobService

public final class BlobCache
extends Object
implements BlobService

The BLOB cache implements a local cache for content-addressable BLOBs. When requesting BLOBs through the getURL(org.apache.flink.runtime.blob.BlobKey) methods, the BLOB cache will first attempt serve the file from its local cache. Only if the local cache does not contain the desired BLOB, the BLOB cache will try to download it from the BLOB server.

This class is thread-safe.

Constructor Summary

Constructors

Constructor and Description
BlobCache(InetSocketAddress serverAddress)

Method Summary

Modifier and Type	Method and Description
void	delete(BlobKey key) Deletes the file associated with the given key from the BLOB cache.
int	getPort() Returns the port of the blob service
URL	getURL(BlobKey requiredBlob) Returns the URL for the content-addressable BLOB with the given key.
void	shutdown() Shutdown method which is called to terminate the blob service.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BlobCache

public BlobCache(InetSocketAddress serverAddress)

Method Detail

getURL

public URL getURL(BlobKey requiredBlob)
           throws IOException

Returns the URL for the content-addressable BLOB with the given key. The method will first attempt to serve the BLOB from its local cache. If one or more BLOB are not in the cache, the method will try to download them from the BLOB server with the given address.

Specified by:

getURL in interface BlobService

Parameters:

requiredBlob - the key of the desired content-addressable BLOB

Returns:

URL referring to the local storage location of the BLOB

Throws:

IOException - thrown if an I/O error occurs while downloading the BLOBs from the BLOB server

delete

public void delete(BlobKey key)
            throws IOException

Deletes the file associated with the given key from the BLOB cache.

Specified by:

delete in interface BlobService

Parameters:

key - referring to the file to be deleted

Throws:

IOException

getPort

public int getPort()

Description copied from interface: BlobService

Returns the port of the blob service

Specified by:

getPort in interface BlobService

Returns:

the port of the blob service

shutdown

public void shutdown()
              throws IOException

Description copied from interface: BlobService

Shutdown method which is called to terminate the blob service.

Specified by:

shutdown in interface BlobService

Throws:

IOException